For some strange reason, I can't use IPTV services such as Perfect Player or XCIPTV, if my Sony Android TV is connected via Ethernet. All other apps like Netflix and Youtube works perfectly well. I can still use Perfect Player and XCIPTV, if the TV is connected via WiFi...just not if connected via Ethernet.
Did you register with a mac adress?
If so, the wifi port has a different mac adress compared to your ethernet port on the tv and that might be the problem since your iptv account could be registered to/with a specific mac adress.
Dont shoot me if im wrong!